Bartonella quintana in Body Lice and Head Lice from Homeless Persons, San Francisco, California, USA

Bartonella quintana is a bacterium that causes trench fever in humans. Past reports have shown Bartonella spp. infections in homeless populations in San Francisco, California, USA. The California Department of Public Health in collaboration with San Francisco Project Homeless Connect initiated a program in 2007 to collect lice from the homeless to test for B. quintana and to educate the homeless and their caregivers on prevention and control of louse-borne disease. During 2007–2008, 33.3% of body lice–infested persons and 25% of head lice–infested persons had lice pools infected with B. quintana strain Fuller. Further work is needed to examine how homeless persons acquire lice and determine the risk for illness to persons infested with B. quintana–infected lice.     

Transmission and Maintenance Cycle of Bartonella quintana among Rhesus Macaques,China

We detected Bartonella quintana in 48.6% of captive rhesus macaques from an animal facility in Beijing, China. Prevalence of infection increased over the period of observation. Our findings suggest that macaques may serve as reservoir hosts for B. quintana and that Pedicinus obtusus lice might act as efficient vectors.     

Prevalence of Head Lice Infestation and Its Associated Factors among Primary School Students in Iran: A Systematic Review and Meta-analysis

Objectives

Head lice infestation is one of the most important health problems, generally involving children aged 5–13 years. This study aims to estimate the prevalence of head lice infestation and its associated factors among primary school children using systematic review and meta-analysis methods.

Methods

Different national and international databases were searched for selecting the relevant studies using appropriate keywords, Medical Subject Heading terms, and references. Relevant studies with acceptable quality for meta-analysis were selected having excluded duplicate and irrelevant articles, quality assessment, and application of inclusion/exclusion criteria. With calculating standard errors according to binomial distribution and also considering the Cochrane''s Q test as well as I-squared index for heterogeneity, pediculosis prevalence rate was estimated using Stata SE V.11 software.

Results

Forty studies met the inclusion criteria of this review and entered into the meta-analysis including 200,306 individuals. Using a random effect model, the prevalence (95% confidence interval) of head lice infestation among primary school children was estimated as 1.6% (1.2–2.05), 8.8% (7.6–9.9), and 7.4% (6.6–8.2) for boys, girls, and all the students, respectively. The infestation rate was found to be associated with low educational level of parents, long hair, family size, mother''s job (housewife), father''s job (worker/unemployed), using a common comb, lack of bathrooms in the house, and a low frequency of bathing.

Conclusion

This meta-analysis revealed that the prevalence of head lice infestation among Iranian primary school children is relatively high with more prevalence among girls. We also found that economic, social, cultural, behavioral, and hygienic factors are associated with this infestation.     

Correlates of HIV Infection Among Transfemales,San Francisco, 2010: Results From a Respondent-Driven Sampling Study

Objectives. We evaluated the use of respondent-driven sampling (RDS) among a high-risk population of transfemales. We also obtained up-to-date epidemiological data on HIV infection and related correlates among this population.Methods. We evaluated the utility of RDS in recruiting a sample of 314 transfemales in San Francisco, California, from August to December 2010 by examining patterns of recruitment and assessing network sizes and equilibrium. We used RDS weights to conduct bivariate and multivariate analyses of correlates of HIV infection.Results. The sample had moderate homophily and reached equilibrium at the eighth wave of recruitment. Weighted HIV prevalence among transfemales was 39.5%. Being a transfemale of color, using injection drugs, and having low educational attainment were independently associated with HIV infection and having a high number of sexual partners and identifying as female were not.Conclusions. RDS performed well and allowed for analyses that are generalizable to the population from which the sample was drawn. Transfemales in San Francisco are disproportionately affected by HIV compared with all other groups except men who have sex with men who also inject drugs.Over the years, many words have been coined to describe individuals born male who identify as female whether they engage in gender transition or enhancement procedures. These words have included “male-to-female transgender,” “transgender women,” and “transwomen.” In some cases, these individuals no longer label themselves as “trans” but rather label themselves solely as “female” or “women.” Furthermore, words such as “women” and “woman,” with their adult association, may alienate adolescent individuals who feel their gender is something other than the one they had at birth. A community process was undertaken in San Francisco, California, to agree on the most inclusive terms. “Transfemales” was thought to capture the spectrum of male-to-female transgender identities while also respecting trans people along the age spectrum. In this article, we have used the word “transfemales” throughout, but we should note that participants identified both as transfemales and as females.Available data on transfemales have suggested extremely high prevalence and incidence of HIV.1 A study carried out by the San Francisco Department of Public Health in 1997 found HIV prevalence among transfemales who inject drugs to be 51.4%—the highest prevalence of any population ever studied in San Francisco—and 26.4% among transfemales who were not injection drug users (IDUs).2 Analysis of voluntary counseling and testing data published in 2001 found HIV incidence to be the highest of any population measured in San Francisco at 13.2% per year among transfemale IDUs and 6.2% per year among transfemale non-IDUs.3 Studies have also shown high rates of sexually transmitted infections among transfemales, particularly gonorrhea and syphilis.4As of December 2010, 194 living AIDS cases and 123 HIV/non-AIDS cases among transfemales had been reported in San Francisco.5 Case reporting conducted by the San Francisco Department of Public Health illustrates the racial/ethnic diversity among transfemales affected by HIV/AIDS. In cumulative reported cases, 29% were White, 31% were Black, 30% were Latino, and 10% were of some other race.5 However, limitations exist to our understanding of HIV prevalence among transfemales on the basis of AIDS and HIV/non-AIDS case reporting alone. Private physicians may not always correctly record transfemales’ gender identity in medical charts, and how many transfemales are misclassified as men who have sex with men or as women is unclear. Underreporting and misclassifications may be common, thus inhibiting accurate reporting of HIV/AIDS diagnoses among transfemales.6On the basis of the available information, San Francisco’s Centers for Disease Control and Prevention–funded HIV Prevention Community Planning Group ranked the transfemale population as the highest priority for HIV prevention funding for 2004–2008.7 Despite the high priority for HIV prevention among transfemales in San Francisco, the population has not become a part of the Centers for Disease Control and Prevention’s national HIV behavioral surveillance system. Yet updated, basic epidemiological data on the prevalence and incidence of HIV among transfemales are needed to determine whether prevention strategies have worked and to plan future efforts at the local level. Unfortunately, studies among transfemales to date have limited external validity because they have primarily been based on convenience samples.1 To our knowledge, few studies have been conducted that could reliably represent the transfemale population. This omission has been understandable—obtaining representative data in hard-to-reach and often hidden populations, especially transfemales, is challenging. Although the 1997 San Francisco Department of Public Health study was rigorous in obtaining a sample size of more than 300, it did not use population-based sampling methods.2 Thus, our secondary aim was to assess the suitability of using a respondent-driving sampling (RDS) study among transfemales. In an effort to fill this gap in data and assess the use of RDS among transfemales, the San Francisco Department of Public Health conducted the Transfemales Empowered to Advance Community Health (TEACH) study to gather up-to-date and representative data on HIV prevalence, HIV incidence, and related risk behaviors among transfemales.     

Tobacco-, Alcohol-, and Drug-Attributable Deaths and Their Contribution to Mortality Disparities in a Cohort of Homeless Adults in Boston

Objectives. We quantified tobacco-, alcohol-, and drug-attributable deaths and their contribution to mortality disparities among homeless adults.Methods. We ascertained causes of death among 28 033 adults seen at the Boston Health Care for the Homeless Program in 2003 to 2008. We calculated population-attributable fractions to estimate the proportion of deaths attributable to tobacco, alcohol, or drug use. We compared attributable mortality rates with those for Massachusetts adults using rate ratios and differences.Results. Of 1302 deaths, 236 were tobacco-attributable, 215 were alcohol-attributable, and 286 were drug-attributable. Fifty-two percent of deaths were attributable to any of these substances. In comparison with Massachusetts adults, tobacco-attributable mortality rates were 3 to 5 times higher, alcohol-attributable mortality rates were 6 to 10 times higher, and drug-attributable mortality rates were 8 to 17 times higher. Disparities in substance-attributable deaths accounted for 57% of the all-cause mortality gap between the homeless cohort and Massachusetts adults.Conclusions. In this clinic-based cohort of homeless adults, over half of all deaths were substance-attributable, but this did not fully explain the mortality disparity with the general population. Interventions should address both addiction and non-addiction sources of excess mortality.Over 2 million people experience homelessness annually in the United States.1 US-based studies of homeless adults have found varied but generally high rates of substance use, including a 68% to 80% prevalence of cigarette smoking,2–6 a 29% to 63% lifetime prevalence of alcohol use disorders,7–13 and a 20% to 59% lifetime prevalence of drug use disorders.7–13 Mortality rates among homeless individuals exceed those in non-homeless people by a considerable margin,14–26 but the extent to which substance use contributes to this disparity is uncertain.In a prior study of homeless adults in Boston, Massachusetts, we found the rate of deaths caused by drug overdose to be approximately 20 times higher than the rate in the general population.14 Similar findings have been documented in New York City, New York, and San Francisco, California.27,28 Overdose deaths draw attention to the overt complications of drug use among homeless people but represent only a single dimension of substance-attributable mortality. Tobacco, alcohol, and drug use may contribute to other common causes of death among homeless people, such as cancer, heart disease, liver cirrhosis, and HIV.14–17 The population attributable fraction (PAF) represents the proportion of these deaths that would not have occurred in the absence of tobacco, alcohol, or drug use.29,30 PAF methods form the basis of studies conducted by the US Centers for Disease Control and Prevention (CDC)31,32 and the Global Burden of Disease investigators33 to quantify the impact of substance use and other risk behaviors on health outcomes.In this study, we describe a novel application of PAF-based methods to estimate tobacco-, alcohol-, and drug-attributable mortality rates among 28 033 adults who used Boston Health Care for the Homeless Program (BHCHP) services from 2003 to 2008. We compared our findings with the Massachusetts general population to examine the degree to which mortality disparities between these groups are driven by substance-attributable deaths. Quantifying the burden of tobacco-, alcohol-, and drug-attributable deaths among homeless individuals has the potential to inform upstream efforts at disease prevention and guide clinical priority setting around the delivery of addiction services for this group of people. Additionally, understanding the extent to which these deaths contribute to the mortality gradient between homeless adults and the general population may provide insight about the ways to reduce this disparity.     

Association Between Time Homeless and Perceived Health Status Among The Homeless in San Francisco

The purpose of this study was to describe the perceived health of the homeless, and to measure the effect of time homeless on perceived health status, after controlling for sociodemographic characteristics and health conditions. The design was cross-sectional; the population was a representative sample of homeless in San Francisco, interviewed on health issues. Analysis of predictors of poor or fair health status was by logistic regression. In this sample of 2780 persons, 37.4% reported that their health status was poor or fair as compared to good or excellent. Reporting poor or fair health status was significantly associated with time homeless, after controlling for sociodemographic variables and health problems including results from screening for HIV and TB (OR = 1.49, 95%CI 1.24–1.79). Comparisons with data from the National Health Interview Survey (NHIS) showed poorer health status among the homeless persons in this study. Standardized morbidity ratios were highest for asthma; there was twice the number of homeless persons reporting asthma, in younger as well as older adults, as would be expected using NHIS rates. There was also an excess of arthritis, high blood pressure and diabetes in those age 18–44 as compared to adults in the Health Interview Survey. The time spent homeless remains associated with self-reported health status, after known contributors to poor health are controlled. Persons who have been homeless for longer periods of time may be the persons to whom health care interventions should be aimed.     

Directly Observed Antidepressant Medication Treatment and HIV Outcomes Among Homeless and Marginally Housed HIV-Positive Adults: A Randomized Controlled Trial

Objectives. We assessed whether directly observed fluoxetine treatment reduced depression symptom severity and improved HIV outcomes among homeless and marginally housed HIV-positive adults in San Francisco, California, from 2002 to 2008.Methods. We conducted a nonblinded, randomized controlled trial of once-weekly fluoxetine, directly observed for 24 weeks, then self-administered for 12 weeks (n = 137 persons with major or minor depressive disorder or dysthymia). Hamilton Depression Rating Scale score was the primary outcome. Response was a 50% reduction from baseline and remission a score below 8. Secondary measures were Beck Depression Inventory-II (BDI-II) score, antiretroviral uptake, antiretroviral adherence (measured by unannounced pill count), and HIV-1 RNA viral suppression (< 50 copies/mL).Results. The intervention reduced depression symptom severity (b = −1.97; 95% confidence interval [CI] = −0.85, −3.08; P < .001) and increased response (adjusted odds ratio [AOR] = 2.40; 95% CI = 1.86, 3.10; P < .001) and remission (AOR = 2.97; 95% CI = 1.29, 3.87; P < .001). BDI-II results were similar. We observed no statistically significant differences in secondary HIV outcomes.Conclusions. Directly observed fluoxetine may be an effective depression treatment strategy for HIV-positive homeless and marginally housed adults, a vulnerable population with multiple barriers to adherence.Depressive, pain, and substance use disorders are highly prevalent among persons living with HIV/AIDS1,2 and among the homeless and marginally housed.3–5 The triple diagnosis of depression, HIV, and substance use poses unique treatment challenges for clinicians: successful management of one condition is often dependent on successful management of the others, and the optimal sequencing of depression treatment, substance use treatment, and stabilization of psychosocial comorbidities remains unclear. Adherence to the entire continuum of HIV care is often hampered by depression6–8 and substance use.9,10 For homeless persons, the need to address subsistence concerns such as obtaining food and shelter may not only adversely affect mental well-being11 but may also divert attention away from medication adherence and regular clinic attendance.12 Timely and effective depression treatment is critical for HIV-positive persons, because depression has been associated with CD4⁺ T-lymphocyte cell count decline,13 progression to AIDS,14 and AIDS-related mortality.15 Yet depression remains pervasively underdiagnosed and undertreated among the homeless16–18 and among HIV-positive persons.19,20Depression treatment might be expected to improve virological or immunologic outcomes through improved adherence, but this has not been conclusively demonstrated.21–23 We therefore sought to determine whether treatment with once-weekly fluoxetine reduced depression symptom severity among homeless and marginally housed persons with comorbid depression and HIV. Because this population faces many psychosocial barriers to successful medication adherence,12,24 in addition to depression,25 we employed a directly observed treatment strategy similar to that used for treatment and management of patients with tuberculosis and HIV.26 This strategy reduced the potential for incomplete adherence to reduce the effectiveness of antidepressant treatment. A secondary aim was to determine whether depression treatment improved antiretroviral therapy (ART) uptake among persons eligible for treatment and ART adherence and viral suppression among treated persons.     

How Many Transgender Men Are There in San Francisco?

The purpose of this study was to estimate the number of transgender men (transmen) adults living in San Francisco. We integrated two population size estimation methods into a community-based health survey of transmen (n = 122) in the San Francisco Bay Area in 2014–2015: the service multiplier and wisdom of the crowds. The median estimate was 806 transmen adults in San Francisco (0.11% of adults) and 4027 in the Bay Area. Considering potential biases, we believe our estimates are conservative. Knowing the denominator of persons at risk for health conditions is necessary for public health planning, surveillance, and impact evaluation.     

Altitude-dependent Bartonella quintana genotype C in head lice, Ethiopia

To determine the presence of Bartonella quintana in head and body lice from persons in different locations in Ethiopia, we used molecular methods. B. quintana was found in 19 (7%) genotype C head lice and in 76 (18%) genotype A body lice. B. quintana in head lice was positively linked to altitude (p = 0.014).     

Drought and Epidemic Typhus,Central Mexico, 1655–1918

Epidemic typhus is an infectious disease caused by the bacterium Rickettsia prowazekii and transmitted by body lice (Pediculus humanus corporis). This disease occurs where conditions are crowded and unsanitary. This disease accompanied war, famine, and poverty for centuries. Historical and proxy climate data indicate that drought was a major factor in the development of typhus epidemics in Mexico during 1655–1918. Evidence was found for 22 large typhus epidemics in central Mexico, and tree-ring chronologies were used to reconstruct moisture levels over central Mexico for the past 500 years. Below-average tree growth, reconstructed drought, and low crop yields occurred during 19 of these 22 typhus epidemics. Historical documents describe how drought created large numbers of environmental refugees that fled the famine-stricken countryside for food relief in towns. These refugees often ended up in improvised shelters in which crowding encouraged conditions necessary for spread of typhus.     

Novel gene isolated from Caligus rogercresseyi: a promising target for vaccine development against sea lice

Sea lice (Copepoda, Caligidae) are the most widely distributed marine pathogens in the salmon industry in the last 30 years. Caligus rogercresseyi is the most important species affecting Chile's salmon industry. Vaccines against caligid copepods have the potential to be a cost-effective means of controlling the infestation and avoid many of the disadvantages of medicine treatments. However, research in the development of such vaccines has begun only recently and approaches used thus far have met with little or no success. In the present study, we characterized a novel gene (denoted as my32) from C. rogercresseyi which has the highest identity with the Lepeophtheirus salmonis gene akirin-2. To assess the function of the gene an RNA interference experiment was developed and a reduction in the number of ectoparasites on fish in the my32-dsRNA treated group was observed. The recombinant my32 protein was used in a vaccination-challenge trial to evaluate its ability to protect against sea lice infestations. A significant reduction in the number of parasites per fish was observed at 24 days post-challenge. These results, together with the delay observed in the development of parasites from the vaccinated group suggest that the major effect of immunization was on the second parasite generation. The results of these experiments suggest that the my32 protein may be a promising target for vaccine development to control sea lice infestations in fish.     

What Is a 2021 Reference Body?

The historical 1975 Reference Man is a ‘model’ that had been used as a basis for the calculation of radiation doses, metabolism, pharmacokinetics, sizes for organ transplantation and ergonomic optimizations in the industry, e.g., to plan dimensions of seats and other formats. The 1975 Reference Man was not an average individual of a population; it was based on the multiple characteristics of body compositions that at that time were available, i.e., mainly from autopsy data. Faced with recent technological advances, new mathematical models and socio-demographic changes within populations characterized by an increase in elderly and overweight subjects a timely ‘state-of-the-art’ 2021 Reference Body are needed. To perform this, in vivo human body composition data bases in Kiel, Baton Rouge, San Francisco and Honolulu were analyzed and detailed 2021 Reference Bodies, and they were built for both sexes and two age groups (≤40 yrs and >40 yrs) at BMIs of 20, 25, 30 and 40 kg/m². We have taken an integrative approach to address ‘structure–structure’ and ‘structure–function’ relationships at the whole-body level using in depth body composition analyses as assessed by gold standard methods, i.e., whole body Magnetic Resonance Imaging (MRI) and the 4-compartment (4C-) model (based on deuterium dilution, dual-energy X-ray absorptiometry and body densitometry). In addition, data obtained by a three-dimensional optical scanner were used to assess body shape. The future applications of the 2021 Reference Body relate to mathematical modeling to address complex metabolic processes and pharmacokinetics using a multi-level/multi-scale approach defining health within the contexts of neurohumoral and metabolic control.     

Household-wide ivermectin treatment for head lice in an impoverished community: randomized observer-blinded controlled trial

Objective

To generate evidence on the effectiveness of household-wide treatment for preventing the transmission of pediculosis capitis (head lice) in resource-poor communities.

Methods

We studied 132 children without head lice who lived in a slum in north-eastern Brazil. We randomized the households of the study participants into an intervention and a control group and prospectively calculated the incidence of infestation with head lice among the children in each group. In the intervention group, all of the children’s family members who lived in the household were treated with ivermectin; in the control group, no family member was treated. We used the χ² test with continuity correction or Fisher’s exact test to compare proportions. We performed survival analysis using Kaplan–Meier estimates with log rank testing and the Mann–Whitney U test to analyse the length of lice-free periods among sentinel children, and we used Cox regression to analyse survival data on a multivariate level. We also carried out a subgroup analysis based on gender.

Findings

Children in the intervention group remained free from infestation with head lice significantly longer than children in the control group. The median infestation-free period in the intervention group was 24 days (interquartile range, IQR: 11–45), as compared to 14 days (IQR: 11–25) in the control group (P = 0.01). Household-wide treatment with ivermectin proved significantly more effective among boys than among girls (P = 0.005). After treatment with ivermectin, the estimated number of annual episodes of head lice infestation was reduced from 19 to 14 in girls and from 15 to 5 in boys. Female sex and extreme poverty were independent risk factors associated with a shortened disease-free period.

Conclusion

In an impoverished community, girls and the poorest of the poor are the population groups that are most vulnerable for head lice infestation. To decrease the number of head lice episodes per unit of time, control measures should include the treatment of all household contacts. Mass treatment with ivermectin may reduce the incidence of head lice infestation and associated morbidity in resource-poor communities.     

Gender-specific Correlates of Sex Trade among Homeless and Marginally Housed Individuals in San Francisco

Objective: Sex exchange is a well-established risk factor for HIV infection. Little is known about how correlates of sex trade differ by biologic sex and whether length of homelessness is associated with sex trade. We conducted a cross-sectional study among a sample of 1,148 homeless and marginally housed individuals in San Francisco to assess correlates of exchanging sex for money or drugs. Key independent variables included length of homelessness; use of crack, heroin or methamphetamine; HIV status; and sexual orientation. Analyses were restricted by biologic sex. In total, 39% of women and 30% of men reported a lifetime history of sex exchange. Methamphetamine use and greater length of homelessness were positively associated with a history of sex trade among women, while heroin use, recent mental health treatment, and homosexual or bisexual orientation were significantly associated with sex trade for men. Crack use was correlated with sex trade for both genders. Correlates of sex trade differ significantly according to biologic sex, and these differences should be considered in the design of effective HIV prevention programs. Our findings highlight the critical need to develop long-term services to improve housing status for homeless women, mental health services for homeless men, and drug treatment services for homeless adults involved in sex work.Weiser, Dilworth, and Neilands are with the Center for AIDS Prevention Studies, University of California, San Francisco (UCSF), San Francisco, CA, USA. Cohen, Bangsberg, and Riley are with Epidemiology and Prevention Interventions (EPI) Center, Division of Infectious Diseases, San Francisco General Hospital, UCSF; Bangsberg is with the Positive Health Program, San Francisco General Hospital, UCSF.The Epidemiology and Prevention Interventions Center, Positive Health Program and Center for AIDS Prevention Studies are programs of the UCSF AIDS Research Institute.     

Characteristics of Emergency Department Visits by Older Versus Younger Homeless Adults in the United States

Objectives. We compared the characteristics of emergency department (ED) visits of older versus younger homeless adults.Methods. We analyzed 2005–2009 data from the National Hospital Ambulatory Medical Care Survey, a nationally representative survey of visits to hospitals and EDs, and used sampling weights, strata, and clustering variables to obtain nationally representative estimates.Results. The ED visits of homeless adults aged 50 years and older accounted for 36% of annual visits by homeless patients. Although demographic characteristics of ED visits were similar in older and younger homeless adults, clinical and health services characteristics differed. Older homeless adults had fewer discharge diagnoses related to psychiatric conditions (10% vs 20%; P = .002) and drug abuse (7% vs 15%; P = .003) but more diagnoses related to alcohol abuse (31% vs 23%; P = .03) and were more likely to arrive by ambulance (48% vs 36%; P = .02) and to be admitted to the hospital (20% vs 11%; P = .003).Conclusions. Older homeless adults’ patterns of ED care differ from those of younger homeless adults. Health care systems need to account for these differences to meet the needs of the aging homeless population.The average age of the US homeless population is increasing. Whereas 11% of the homeless population was aged 50 years or older in 1990, this percentage had increased to 32% by 20031 and has continued to rise since then.2 The median age of single homeless adults has increased from 37 years in 19901 to between 49 and 50 years today.2,3 This trend is thought to be because of the aging of individuals born in the second half of the baby boom generation (those born 1954–1965), who have a higher risk of homelessness than do other age cohorts.3 Most homeless adults aged 50 years and older are aged between 50 and 64 years, with adults aged 65 years and older making up less than 5% of the total homeless population.1,3In the general population, adults aged 50 to 64 years are considered middle aged and have lower rates of chronic conditions than do those considered elderly, adults aged 65 years and older.4,5 However, homeless adults aged 50 years and older have rates of chronic illnesses and geriatric conditions similar to or higher than those of housed adults 15 to 20 years older, including conditions often thought to be limited to the elderly, such as falls and memory loss.6,7 Because middle-aged homeless adults face the same geriatric problems as do elderly housed adults, experts consider them to be elderly when aged 50 years, despite their relatively younger age.6,8 Similar patterns of premature aging have been found in other vulnerable populations, including prisoners9 and patients with developmental disabilities.10Despite the growth of the older homeless population, relatively little is known about use of health services among older homeless adults. Homeless health services and research have focused on problems that are common among younger homeless adults, including infectious disease,11 substance use,12 and mental illness.13 The few studies that have focused on older homeless adults found that they have medical problems that differ from those of younger homeless adults, including higher rates of chronic illnesses6,14 and geriatric syndromes6 and lower rates of substance use.15 New frameworks for providing care to the vulnerable and growing older population are needed but cannot be developed until more is known about their use of health services.Homeless adults aged 50 years and older use the emergency department (ED) frequently and at rates nearly 4 times those of the general population.16–18 Knowledge about ED care that older homeless adults receive may allow researchers and clinicians to design interventions to reduce use of the ED and improve ED care for this vulnerable older population. Therefore, we have identified the demographic, clinical, and health services characteristics of ED visits in older versus younger homeless adults, using a nationally representative survey of US ED visits.     

Bed bug infestations in an urban environment

Until recently, bed bugs have been considered uncommon in the industrialized world. This study determined the extent of reemerging bed bug infestations in homeless shelters and other locations in Toronto, Canada. Toronto Public Health documented complaints of bed bug infestations from 46 locations in 2003, most commonly apartments (63%), shelters (15%), and rooming houses (11%). Pest control operators in Toronto (N = 34) reported treating bed bug infestations at 847 locations in 2003, most commonly single-family dwellings (70%), apartments (18%), and shelters (8%). Bed bug infestations were reported at 20 (31%) of 65 homeless shelters. At 1 affected shelter, 4% of residents reported having bed bug bites. Bed bug infestations can have an adverse effect on health and quality of life in the general population, particularly among homeless persons living in shelters.     

Cercarial Dermatitis Transmitted by Exotic Marine Snail

Cercarial dermatitis (swimmer’s itch) is caused by the penetration of human skin by cercariae of schistosome parasites that develop in and are released from snail hosts. Cercarial dermatitis is frequently acquired in freshwater habitats, and less commonly in marine or estuarine waters. To investigate reports of a dermatitis outbreak in San Francisco Bay, California, we surveyed local snails for schistosome infections during 2005–2008. We found schistosomes only in Haminoea japonica, an Asian snail first reported in San Francisco Bay in 1999. Genetic markers place this schistosome within a large clade of avian schistosomes, but do not match any species for which there are genetic data. It is the second known schistosome species to cause dermatitis in western North American coastal waters; these species are transmitted by exotic snails. Introduction of exotic hosts can support unexpected emergence of an unknown parasite with serious medical or veterinary implications.     

Characteristics of persons with chronic hepatitis B--San Francisco, California, 2006

Chronic hepatitis B is the most common cause of cirrhosis and liver cancer worldwide. Approximately 45% of the world's population lives in regions where chronic hepatitis B virus (HBV) infection is endemic, including most of Asia and the Pacific Islands, Africa, and the Middle East. Nearly one fourth of the population of San Francisco was born in Asia and the Pacific Islands. In 2006, the San Francisco Department of Public Health (SFDPH) received reports consistent with probable chronic HBV infection for 2,238 persons. To characterize persons with reported confirmed chronic HBV infection in San Francisco in 2006, SFDPH collected additional data on a subset of 567 cases reported to the SFDPH chronic hepatitis B registry. Eighty-four percent of the persons were Asians/Pacific Islanders (A/PIs), 80% of whom were foreign born. Fewer than half had been referred to a gastroenterologist/hepatologist for evaluation at the time of reporting. Persons with chronic HBV infection can benefit from medical care by providers with expertise in viral hepatitis. In addition, close contacts of infected persons should be screened and offered vaccination if found to be susceptible to HBV infection. Culturally appropriate counseling for and follow-up of persons with chronic HBV infection and their contacts could help reduce the transmission of HBV infection.     

Increasing Incidence of Invasive Group A Streptococcus Disease in First Nations Population,Alberta, Canada, 2003–2017

The incidence of invasive group A Streptococcus (iGAS) disease in the general population in Alberta, Canada, has been steadily increasing. To determine whether rates for specific populations such as First Nations are also increasing, we investigated iGAS cases among First Nations persons in Alberta during 2003–2017. We identified cases by isolating GAS from a sterile site and performing emm typing. We collected demographic, social, behavioral, and clinical data for patients. During the study period, 669 cases of iGAS in First Nations persons were reported. Incidence increased from 10.0 cases/100,000 persons in 2003 to 52.2 cases/100,000 persons in 2017. The 2017 rate was 6 times higher for the First Nations population than for non–First Nations populations (8.7 cases/100,000 persons). The 5 most common emm types from First Nations patients were 59, 101, 82, 41, and 11. These data indicate that iGAS is severely affecting the First Nations population in Alberta, Canada.